NO317712B1 - Device for continuous progress and flexible deposition of pulp. - Google Patents

Description

DEVICE FOR CONTINUOUS PROGRESS AND FLEXIBLE DEPOSIT OF MASS

The invention relates to a device designed for the transport of mass, such as coarse and tough drilling waste, in a pipe system by means of an internal air flow preferably generated by a vacuum suction device, and the transfer of said coarse and tough mass from the pipe system to the atmospheric environment by means of of a discharge valve.

The purpose of the invention is to provide a device which, by means of a pipe system, with internal air flow preferably generated by a vacuum suction device, will function stably to transport mass, for example drilling waste, from a specified area and deposit said mass essentially continuously into the atmosphere environment, preferably in a collection container, in a safe, efficient and environmentally sound way, while the device must be space-saving and flexible with regard to the deposition point both in the horizontal and vertical planes.

In connection with drilling for oil and gas offshore and on land, large quantities of drilling waste are produced which must be temporarily stored on the drilling rig or drilling installation, hereinafter referred to as the drilling rig.

As borehole fragments, so-called cuttings, come up from the borehole, the mass from the borehole is sieved to separate parts of the liquid and the fine mass from the coarse mass. The liquid and the fine mass are brought back to the borehole and used in the further drilling operation, while the coarse mass has to be transported away. One of the methods used to transport the coarse mass away from the screening machines is to generate a powerful air flow in a pipe system by connecting a vacuum suction device to the pipe system in which the mass is transported. One of the major challenges when using a vacuum system such as the one discussed here for the transport of mass is to transfer the mass to the atmospheric environment while maintaining the air flow in the pipe system.

A known solution for transferring drilling waste from a vacuum system to the atmospheric environment is that said vacuum pipe system is connected to a silo-like tight container, in industry terminology called a loading tower. Such loading towers have a large internal cross-sectional area in the direction of flow of the air in the pipe system in relation to the cross-sectional area of the vacuum pipe system which leads the drilling waste into said loading tower. This difference in area results in the flow rate being reduced for the air and drilling waste as the mixture is carried from the pipe system into the loading tower. As a result, the drilling waste is deposited in the loading tower. When the loading tower is filled with a certain amount of drilling waste, it must be emptied. This usually happens by an automatic valve device in the bottom part of the loading tower being opened at a pre-set weight. From said automatic valve device, the drilling waste is transferred into so-called large sacks or transport containers which are placed under said valve device. Significant parts of the process of removing full and placing empty cargo containers under the loading tower consist of manual operations where several people must be involved in a work environment where the risk of accidents is very high and where fatal accidents have occurred.

In normal production offshore, approx. 20 tonnes of drilling waste per hour. A normal loading tower with a height of 7 m has a capacity of approx. 5 tonnes of drilling waste. This involves emptying the loading tower approx. 4 times per hour.

When emptying the loading tower is in progress, the tower must either be isolated from the vacuum system or the transport of drilling waste from the screening facility must be stopped while emptying is carried out, which means that the drilling operation must be stopped. In order to avoid such stoppages in the drilling operation, it is common to install two loading towers which are alternately bubbled to the flow of air and drilling waste in the pipe system so that one of the loading towers is connected to the flow of air and drilling waste and is filled with drilling waste, while the other loading tower is isolated from the flow of air and drilling waste while emptying of drilling waste. An arrangement with two loading towers occupies a relatively large part of the often limited area available on a drilling rig. An arrangement with a loading tower that is discussed here is a stationary facility that is not flexible with regard to the location of the big bag or the transport container that is to be filled with drilling waste, which usually involves several movements of the individual big bag or transport container in the processes related to the storage of emptying, filling and storing full large sacks or transport containers.

From EP-A2-47615 it is known a container which can be emptied into the atmospheric environment even if a vacuum is maintained in the container, which allows emptying and filling of the container to take place continuously and independently of each other. The container is filled via two suction tubes with respective pneumatic valves which are opened/closed to propel the material forward. However, the container is designed to transport dry and loose materials such as coal, and it is thus not suitable for transporting tough materials such as coarse and tough drilling mud.

The purpose of the invention is to remedy the disadvantages of known technology by providing a device for the continuous transport of drilling waste, whose deposition point from the transport system is preferably flexible.

The purpose is achieved by means of a device whose advantageous constructive features are described in the following and stated in the characteristic part of the independent claim 1.

A preferably flexible dispensing device is in fluid communication with a vacuum pipe system which is connected to a vacuum suction in a known manner, and is integrated in a movable arm which is preferably rotatable, in the horizontal plane of the position of use, attached to the drilling device either directly or via a substantial vertical column device placed between the drilling device and said preferably rotatable movable arm.

The pipe system can consist of rigid pipes, flexible hoses or a combination of these.

The second end point of the preferably movable arm is provided with a discharge device which essentially consists of a container under which an air/vacuum-tight discharge valve is fixed, which ensures that the vacuum flow in the pipe system is maintained, even during discharge of the mass.

The preferably movable arm of a type known in and of itself is provided with at least one, but preferably two or more, preferably about the horizontal axis rotatable joints placed between the arm's attachment point or end point in which the output device is placed, and in such a way that the arm with the at least one joint enables that the distance of the output device from the arm's mentioned connection point on the drilling installation can be varied in the position of use both in the horizontal and vertical plane. The end part of the arm can advantageously be telescopically slidable. This possibility of movement of said delivery device entails major logistical advantages as several large sacks or transport containers can be placed within the reach of the delivery device and filled and stored full before transport away, without them having to be moved on the deck of the drilling device. In addition, the removal of full and the supply of empty big bags or transport containers can be carried out at the same time as the filling operation of other transport containers.

By further applying known techniques to allocate for remote control the preferably movable arm and the dispensing device's dispensing rate, a significant improvement in terms of personnel safety and efficiency in the handling of large sacks or transport containers is achieved.

In order to achieve continuous deposition of mass from the discharge device placed on the preferably movable arm, the air and mass flow in the pipe system that transports the drilling waste to the discharge device must be maintained. There is therefore a need for a type of discharge valve that can withstand the loads that the coarse and tough drilling waste represents and which at the same time prevents air from disappearing from or being added to the air flow in the closed system. There are no known discharge valves suitable for the aforementioned purpose.

The purpose of the invention is to provide a device consisting of a discharge device which is suitable for transferring mass from a closed pipe system, in which coarse and tough drilling mud is moved with the help of a powerful air flow generated by, for example, a vacuum suction device connected to the pipe system, to the atmospheric environment outside the pipe system, at the same time that the main part of the air flow is maintained in the pipe system. The purpose is achieved by connecting a vacuum pipe system to a dispensing device which consists of a container under which a dispensing valve is fixed. Said vacuum pipe system is connected to the container with an inlet pipe and an outlet pipe, preferably in the upper horizontal end part of the container in the use position. The container's primary function is, in a known manner, to provide an increase in volume relative to the pipe system in order to thereby achieve a speed reduction of the air and particle flow as the air and particle flow enters the container. This speed reduction results in the particles in the air flow falling towards the bottom part of said container, and the air flows out of the container and into the pipe system through the outlet pipe in the container's mentioned upper end part.

In order to further achieve a reduction of the speed of the air flow in the container in relation to the air flow in the pipe system from said container, the dimension of the pipe system, which in the situation of use leads the air and particle flow into the container, is smaller than the dimension of the pipe system which directs the air flow out of the container.

The deposited mass in the bottom part of the container falls out through a recess in said bottom part and into a discharge valve firmly attached, preferably by means of a flange connection, to the lower part of the container.

The discharge valve consists of a cylinder element with the longitudinal axis of the cylinder essentially in a horizontal position. Coinciding with the longitudinal axis of the cylinder element, a shaft is fitted from which preferably three or more rigid plate elements are fixed, each projecting to the cylinder wall and to the end surfaces of the cylinder. Said preferably three or more rigid plate elements divide the interior space of the cylinder into essentially equal-sized, cylindrical sector-shaped chambers.

Said shaft is stored in a manner known per se in the center of two disk-shaped end plates placed on said cylinder's end surfaces by means of preferably four tension bolts which are guided on the outside of the cylinder element of the delivery device and through recesses in said end plates where nuts are placed. The shaft is connected to a drive source, for example hydraulic or an electric motor, in a known manner and the shaft with said 3 preferably three or more plate elements rotates inside the cylinder element when driving force is applied to the shaft.

In the upper and lower parts of the cylinder element in the position of use, two recesses are formed on which, on the outside of the cylinder element, pipe stubs are fixed and protrude substantially perpendicularly and vertically from the surface of the cylinder element. A fixed flange can advantageously be attached to said pipe connection where the flange of the upper pipe connection can be connected to the flange at the bottom of the container.

In order to achieve an essentially airtight connection between said rigid plate elements and the inner surfaces of the cylinder, a flexible replaceable gasket material, for example consisting of aramid fiber, is placed in a recess in the edge surfaces of the rigid plate elements, which in the use situation is in contact with the said inner surface of the cylinder surfaces.

As previously mentioned, drilling waste is a tough material. In order to be able to remove any so-called "bridging" of mass in the lower part of the dispensing device's container, above the dispensing valve's three or more rigid plate elements, the container can be provided with one or more nozzles that can be connected to pressurized fluid. The optionally at least one nozzle is placed in the lower part of the container of the dispensing device.

In one or both end surfaces of the discharge valve, one or more nozzles can also be fitted, the purpose of which is twofold; to add fluid under pressure to clean the chambers in the discharge valve of any deposits, and possibly to add oil or another chemical or substance suitable for lubricating the gasket material that seals between the three or more rigid plate elements that are in contact with the cylinder's internal surfaces.

In order to achieve the intended separation of solid particles and air in the container of the dispensing device, it is desirable, but not necessary, that there is a layer of mass in the lower part of the container which helps to isolate the individual chamber from the container's air flow so that air is not removed or added to the closed system via the space in the individual chamber. Experiments also show that wear on the seals is reduced when these are isolated from the air in the container.

In order for the particles to be deposited in the container, it is very important that the particles have a sufficient "falling height". If the required drop height is not present, the particles will follow the air flow out of the container. It is therefore crucial to achieve the intended separation of the particles that mass is not filled too high in the container of the dispensing device.

In order to be able to optimize the level of mass in the container of the dispensing device, a weighing cell can be arranged for this which controls the rotation speed of the dispensing valve in a known manner and which in addition also stops the flow of air and particles in the closed pipe system if the level in the container exceeds a predetermined level.

The load cell's control of the output valve's rotation speed can be overridden by the operator's remote control of rotation speed.

In what follows, a non-limiting example of a preferred embodiment is described which is illustrated in the accompanying drawings, where;

Fig. 1 shows an elevation of a device according to the invention seen from the side where a dispensing device is fixed at the end of a movable arm; Fig. 2 shows a sectional cross-section A-A of the arm in fig. 1; Fig. 3 shows an enlarged view of the dispensing device in fig. 1; Fig. 4a shows an elevation of the discharge valve; Fig. 4b shows an elevation of the discharge valve's rotor; Fig. 4c shows a cross-section B-B of the rotor of the discharge valve in fig. 4b; Fig. 5a shows the discharge valve's end plate seen from the side facing the cylinder element in the direction of use; Fig. 5b shows the end plate of the discharge valve in fig. 5a seen from C-C in Figure 5a.

In Figure 1, the reference number 1 denotes a dispensing device which is movably suspended in an arm 10 in an attachment point 11'. The arm 10 is of a type known per se and consists of two boom elements 10' and 10'', where 10'' is telescopic, which are connected in a rotatable joint 11 and placed on the drilling device via an essentially vertical column device 15 which can rotate in the horizontal plane of the position of use about a rotatable attachment 17 of a known type per se.

In the column device 15, in the arm 10' and in parts of the arm 10'', two pipes 5 and 6 are routed which protrude from said arm 10'' near the output device 1, and are connected to the upper horizontal end cap 22 of said output device 1 via flange connections .

Said end cap 22 forms the top of the container 20 of the dispensing device 1, which in its upper and middle part in the use position has an essentially vertical wall part. The container's lower part 20' consists of an essentially conical part which tapers towards the bottom part of the conical part 20, where said container 20' is, via a flange connection 25, connected to a discharge valve 30.

The pipe system 5, 6 is connected to a vacuum suction device in a manner known per se so that an air flow is generated suitable for transporting coarse and tough drilling waste in the pipe 5 from another area (not shown) via the container 20, 20' and the discharge valve 30 to a transport container 19.

Due to the large cross-section of the container 20, 20' relative to the cross-section of the supply pipe 5, the flow rate for air and drilling waste will decrease considerably as it flows into the container 20 at the container's upper end cap 22. This speed reduction means that the drilling waste is separated from the air flow and falls towards the bottom of the container 20'. The air, now essentially free of drilling waste particles, is sucked out of the container 20 through the return pipe 6 in the container's upper end cap 22.

In order to further reduce the speed of the air and particle flow inside the container 20, the supply pipe 5 is of a smaller dimension than the return pipe 6.

In order to prevent possible "bridging" of drilling waste particles over the discharge valve 30, which means that said drilling waste particles do not fall through the container 20, 20', the container 20' is provided with a nozzle 27. The nozzle 27 can be connected (not shown) to a fluid which under high pressure is fed into the container 20' and dissolves the solid mass.

The drilling waste, which is separated from the air flow in the supply pipe 5 and has fallen into the lower part of the container 20', falls further into the discharge valve 30, which is an air and vacuum-tight sluice valve that brings the particles over to the atmospheric environment above the transport container 19.

Figure 4a shows a discharge valve 30 according to the invention with a cylinder element 31 which is provided with two flange pipe fittings 32, 32' in the cylinder element 31, in the use position, top and bottom. The two end parts of the cylinder element 31 are closed by the fact that two end plates 40 are sealingly and firmly attached to said end parts by means of four tension holes 33 guided through recesses 46 in the end plates 40 and on the outside of the cylinder element 31 of the discharge valve 30.

The tension bolts 33 are subjected to tension by means of nuts 39 placed on the outside of the end plates 40.

Figures 4b and 4c show the rotor 34 of the discharge valve 30, which consists of a shaft 35 with smaller shaft pins 37 in the center of the shaft 35's two end surfaces and where four rectangular plate elements 36 are attached essentially perpendicular to the shaft 35's surface. The longitudinal direction of the plate elements 36 is essentially parallel to the longitudinal direction of the shaft 35.

The free edge surfaces 38 of the plate elements 36, which in the situation of use face the cylinder element 31 {fig. 4a) inner casing surface and end plates 40 and, in the longitudinal direction of the edge fins 38 are provided with an essentially centered recess 42 in which a gasket 44 is placed which touches the cylinder element 31's (fig. 4a) inner casing surface and end plates 40, whereby the four airtight chambers are formed, each delimited by the shaft 35, the plate elements 36 with gaskets 42 and the cylinder element 31.

It is important for the invention that the gaskets 42 on the plate elements 36 of the rotor 34 form an air and vacuum-tight surface against the inner surface of the cylinder 31 so that the openings in the top and bottom parts of the discharge valve 30 do not escape or add air to the closed system which is made up of the pipe system 5, 6 and the discharge container 20 together with the equipment which generates the air flow (not shown).

The end plate 40, which is shown in figures 5a and 5b, is provided with 4 recesses 46 for tension bolts 33, a centered in and of itself known bearing bushing 47 complementary to the axle pin 37 (fig. 4b), and two nozzles 48.

The nozzles 48 can be connected (not shown) to a fluid applied pressure to clean the chambers in the discharge valve 30 of any deposits from the drilling waste, or the nozzles can be connected (not shown) to oil or another chemical or substance suitable for lubricating the seals 42 (fig. 4c) which seals between the four plate elements 36 (fig. 4b) which are in contact with the inner surfaces of the cylinder element 31 (not shown).

In order to ensure accurate centering of the end plate 40, the side of said end plate 40 which in the position of use faces the cylinder element 31 (fig. 4a) is provided with a milling that projects from the outer edge surface of the end plate 40 towards the center in such a way that the milled part of the end plate 40 rests against the end surface of the cylinder element 31 (fig. 4a) and the unmilled part of the inside of the end plate 40 is precisely adapted and protrudes slightly into the cylinder element 31 (fig. 4a).

When the rotor 34 rotates, by means of, for example, an electric motor (not shown), the chamber of the rotor 34, which faces upwards towards the opening of the discharge container 20', is filled with drilling waste particles. The particles are kept closed in the chamber until the chamber is turned to face downwards, whereby the particles fall out through the opening of the discharge valve 30 in the bottom part.

The arm 10's ability to move in the vertical and horizontal plane, together with the dispensing device 1's maintenance of the vacuum-generated air flow in the pipe system 5, 6, produces significant logistical and safety advantages, as several large bags (not shown) or transport containers 19 can be placed within the reach of the arm 10 with the dispensing device 1 and are filled and stored full before transport away, without having to be moved on the deck of the drilling rig. In addition, removal of full and supply of empty sacks or transport containers 19 can be carried out at the same time as the filling operation of other transport containers 19 is carried out.

As alternative embodiments, the output device 1 can be connected to a vacuum pipe system 5, 6 in an arrangement where a movable arm 10 is not included, or that the movable arm is replaced by a lifting device in which the output device 1 with the pipe system 5, 6 is suspended.

Claims (6)

1. Discharge device (1), composed of a container (20) which in an upper part is connected to a pipe system (5,6) in which drilling waste is moved by means of an air flow and where said container (20) in its lower part (20') ) is provided with an outlet to a delivery valve (30) fixed to the container (20') which consists of a cylinder element (31) and which is provided with recesses in the upper and lower part with the longitudinal axis of the cylinder element (31) essentially in a horizontal position and where the coincident with the longitudinal axis of the cylinder element (31) is placed a rotor (34) stored in the end plates (40) of the cylinder element (31), characterized in that the rotor (34) of the discharge valve (30) is provided with three or four plate elements (36) with gaskets (44) placed in grooves (42) on all the plate elements' (36) free edge surfaces (38) to form an essentially airtight surface against the cylinder element's (31) inner mantle surface and end plates (40), and where the container's (20) preferably lower part (20') and utma one or both end plates (40) of the valve (30) are provided with at least one nozzle (27, 48) which can be connected to a fluid supply. 2. Discharge device as stated in claim 1, characterized in that the gaskets (42) of the plate elements (36) are replaceable. 3. Delivery device according to any one of claims 1-2, characterized in that the delivery device (1) is attached to an arm (10) which is movable in the horizontal and vertical planes. 4. Discharge device according to claim 3, characterized in that the arm (10) movable in the horizontal and vertical planes is provided with a telescopically displaceable end part (10''). 5. Dispensing device according to any one of claims 1-4, characterized in that the dispensing device's (1) dispensing rate is controlled automatically by means of a weighing cell placed between the dispensing device's container (20) and the movable arm (10). 6. Delivery device according to claims 1 and 5, characterized in that the flow of air and particles into the delivery device (1) is stopped by a signal from the weighing cell when the weight in the delivery device (1) exceeds a predetermined value.